Análisis experimental del transporte de sedimentos en la derivación a 90 grados de un canal de laboratorio en condiciones de lecho fijo.

Abstract

The present study is developed in the experimental facility that represents a channel with 90-degree diversion, located at “Centro de Investigaciones y Recursos Hídricos CIERHI” of Escuela Politécnica Nacional, with the purpose of carrying out the experimental analysis of sediment transport and turbulence, under conditions of a set flow on a fixed bed thickness of sand. Test of bed load movement determined the hydrodynamic parameters, 40 l/s flow, average velocity of 27.8 cm/s, in a turbulent subcritical regime with a slope of the 0.1% channel. Then, instantaneous velocity measurement campaign was carried out in the three “xyz” components through Doppler velocimeter (ADV), for turbulence parameters calculation, such as Reynolds stresses, turbulence intensities and Kolmogorov scales. Finally, the lifting of the batimetry was carried out for distribution analysis of sand in the resulting undercut and sedimentation areas, and thus check the Bulle hypothesis according to sediment unbalance transported towards the lateral intake. The velocity vectors in the main channel evidence from velocities near the average in the upstream of the lateral intake, that is 27.8 cm/s, to velocities of 60 cm/s along the derivation, as well as stationary flows and in opposite way downstream the channel, due to the recirculation of the flow product of the vorticities generated in the contact area of both areas. In case of batimetry, maximum undercuts of up to 19.70 cm are recorded in the main vorticities areas, in this way the Bulle hypothesis with volumes of 33% sand expelled through the model was checked.